Stop mechanism for die presses



Jan. 5, 1926. "1,568,083

H. OSSWALD STOP MECHANISM FOR DIE PRESSES Filed Nov. 10, 1923 2Sheets-Sheet 1 i I %W wwevitoz Jan. 5 1926. Y

H. OSSWALD STOP MECHANISM FOR DIE PRESSES Filed Nov. 10. 1923 2Sheets-Sheet 2 *4 %mm1 M04126 Patented Jan. 5, 1926.

UNITED stares HERKAF OSSWALD, F 7 NIVERVILLE; NEW YORK.

sror' M'scHAmsM FOR Dis PREssEs.

Application filed November 10, 1923.- Serial No. 673,895.

To. all whom it may concern:

Be it known thatI, HERMAN OSSWALD, a citizen of the United States, andresidentof Niverville, in the conntyof Columbia and State of New York,have invented certain new and useful Improvements in Stop Mechanisms forDie Presses, of which the following is a specification.

This invention relates to stop mechanism for die presses of the typedisclosed in my U. S. Patent No. 1472810 dated November 6, 1923, and theobject of the invention is to provide generally improved novel means forautomatically stoppingthepress in the event the work, that is the blankscut from the metal operated upon by the press, is not properlypositioned to be acted upon by the punches used for cutting or formingthe blanks to produce the desired article.

In the said patent there is disclosed a press having aplurality ofpunches and dies for forming the articles. The material from which theblanks are formed is sheet metal or similar material, and the blanks arecon= veyed from one co operating punch and die to another, adjacent,co-operating punch and die. The conveyingmeans is in the form of aslide, cal-led a transfer slide; The stop mechanism actuates a'registering or safety member in the forinof' a pin ads ed to enter ahole in the said slideduring the operation. If, however, for somereason, the slide is so o erated that the safety mem her" can not entersaid hole in the slide,

means are provided for stopping the ma chine.

Accordingly my invention is embodied in a safety or stop mechanism fordie presses arranged and designed as" hereinafter set forth, whilereferenceis-ha'd to the accent-- paigying' drawings in which ig'. 1 isan outlineview in elevation of a die press embodying the invention. I

, Fig; 2 is a iew in elevation of the right side of the press showingthe safety stop mechanism with parts section onthe line- 22 of FigureFig. 3 isa sectional View on substantially the line3+3 of Figure 2. v

Figure 4' is a rear View of Figure 2 lookiing in the'gdirection of arrow4 Figure 2.

Fig. 5 is a perspective View of the safety stop cam: used the safetystop mechani m.

ig. 6 is apersp'ective View of the safety stop.

F ig'. 7 is detail View of the safety stop and the clutch dog.

Fig. 8 is a View of the clutch dog.

Fig; 9 is a perspective View of the inside hub portion of the flywheel.

Referring to Figure 1 the r'eferencenum'er'al 1 denotes the main frameof the press. At the top is mounted the drii' ing' shaft 3, whichoperates a vertically reciprocating slide 4,- suitab'ly guided. Theslide at car ries a punch holder 6. The frame supports a bolster 7. Thepunches are arranged in a single row in the punch holder 6 In thedrawing only the first punch for blanking or cutting the blank from thesheet metal is shown. The cutting punch cooperates with a cutting dielocated within a die base 25. The dies are supported in a die bed 8. Themeans for conveying the blanks is in the form of a transfer slide 13which moves in a slot 11 in the die bed.

The transfer slide 13 is moved or r'ccip'ro cated lengthwise ofthemachine by means of an arm 183 carried by a rock shaft 182. The latteris rocked or oscillated from the driying shaft 3 by means of a cam 211,cam roll 213-, link 180" and arin181 in an obvious manner; g

For details of the above described parts reference is bad to theaforesaid patent, said parts being shown and describedherein onlyenerally.

Referring now more specifically to the safety or stoppinginea'ns, thenumeral 225', Fig. 1, denotes bracket secured to the frame 1. 226 is arod which slides in the bracket.

The rod carries an arm 227 in which is I adju'stab'ly secured a safetystop pin 228 adapted to enter an apeiture'or hole 229' in thetransferslide 13, see Figure 1. The safety rod 226 is pivoted at itsupper end to a safety rod arm 231 pivoted onthe frame at 232'. Thefreeend of said arm is pivoted to alink 238 which in turn is pivoted to asafety cam lever 234. The latter is: pivoted to the frame at 23 5' andcarries a cam roll 236 which runs on the safety stop (351111 237. Therod 226' is surrounded by a spring 280 which assists in bringing the roddown and keeps the roll 236 on the earn 287. During the regularoperation of the press the safety rod is operated insynchronisni withthetransfer slide so that the safety pin 228 enters the safety hole 229once during each revolution of the press. If, however, for some reasonor other, the slide 13 is so operated that the stop pin 228 can notenter the hole 229, thesafety rod 226 will of course remain in anelevated abnormal position and a catch 238 on the said arm 231 willremain in the path of a tooth 239 carried by the safety stop 240, Figure2.

The safety stop is in the form of a ring 240 loosely carried on theshaft 3 and provided with one tooth 239 adapted to cooperate with thesaid catch 238 and another tooth adapted to cooperate with the switch242 by engaging a step 243 thereon.

The said two teeth are in different planes as shown. Adjacent the safetystop there is pinned to the shaft 3 a clutch ring 245 which is anannular member provided with a groove 246 in which lies a spring 247.The

one end of the spring bears against the end 248 of said groove 246. Theother end of the spring bears against a lug 249, said lug 249 being theone end of a clutch dog actuating member 250 which is carried in the 3safety step 240 and which has a head'25l which plays in a cut out 252 inthe safety stop cam 237, see' Figures 2 to 6.

As seen in Figure 3, the shaft 3 is enlarged between the frame 1 and theflywheel 254,

the enlarged portion being marked 255. In

the latter is cut a groove 256 in which slides the clutch dog 257,Figure 8, which has a notch258 with a cam surface 259. The notch 258 isof a width equal to the width of the safety stop 240 and the latteroccupies the said notch. In addition, the safety stop is provided with acut out 259 having a cam surface 260. The clutch dog is provided with arecess 277 which is occupied by a spring 262 which tends to move the doginto engagement with the flywheel 254. The latter is provided with twodiametrical- 1y opposite sloping or inclined surfaces 263 anc 264 whichlead into a diametrically cut groove 265 and opposite the said surfacesthe flywheel is provided with hardened steel pins of which only theheads 266 appear in Figure 9.

The aforesaid switch 242 is mounted to slide in a housing 267 and isurged towards the clutch mechanism by a spring 268. The switch may bewithdrawn from the clutch mechanism by operating the treadle rod 269which is in pivotal engagement at 270 with an arm 271 pivoted at 272 towhich the switch stem 273 is pivoted at 274. The stem 273 is screwedinto the switch. Holes 275 are provided in the press frame for securingthe switch housing 267 in different adjusted positions by means of abolt 276.

The operation is as follows: hen the press stands still the clutch dog257 lies wholly within the groove 256 in the shaft and is withdrawn fromthe flywheel which we will assume is rotating. In this case the switch242 will be in its forward position, the tooth 241 will be up againstthe step 243 on the switch and the circular spring 247 will becompressed between the groove 246 and the lug 249, the head 251 of themember 250 being against the one end of the out out 252 in the safetystop cam 237. The relative position of the safety stop 240 and clutchdog 257 will be as in Figure 7. The dog spring 262 within the recess 277will be compressed. It is to be noted that in Figures 2, 3 and 4 theparts are shown in running position.

When it is desired to start the press, the

operator puts his foot on the treadle, (not shown) and the treadle rod269 is depressed thereby withdrawing the switch 242 and releasing tooth241 on the safety stop. Consequently the latter is free to rotate and isthrown in the direcion of rotation (anticlockwise in Figure 2) by thespring 247, which acts between the end 248 of the groove 246 in theclutch ring (which is secured to the shaft) and the lug 249 carried bythe safety stop 240 (which is loose on the shaft and free to operate).This movement brings the cut out 259 in the safety stop opposite theclutch dog, consequently the latter is re leased and the spring 262throws the clutch dog into engagement with the flywheel, the dog slidingdown one of the surfaces 263 or 264 and against one of the hardenedsteel pins 266. Thus the flywheel is clutched to the shaft and the pressstarts operating.

During the operation the safety rod lever 231 is operated regularly bythe safety stop cam to raise and lower the safety stop pin 228 asexplained above. The parts are so timed, that the catch 238 on saidlever 231 is down to permit the tooth 239 on the safety stop 240 to passby, while the tooth 241 cannot engage the step 243 on the switch becausethe latter is withdrawn.

WVhen the operator takes his foot off the treadle, the switch 242 willbe moved inward by the spring 268, consequently said switch will be inthe path of the tooth 241 (these two elements being in the same plane)and when they meet, the switch will stop the safety stop 240.Immediately thereafter the rotating clutch dog will run against the camsurface 260 of the safety stop and will be withdrawn from the flywheeland the press will stop. From the moment the stop tooth 241 engages thestop 243 on the switch and until the clutch dog has been withdrawn fromthe flywheel the safety stop cam 237 will keep rotating with the shaftbut will not affect the other parts because the cut out 252 in the camwill run over the head 251 until the head reaches the end of said outout 252 which of course is proportioned so as to be long enough topermit the dog to be disengaged from the fly wheel.

Similarly,-if during the running of the press, the safety stop pin isunable to properly re ister and enter the safety hole 229 in the slide13, the catch 238 on the arm 231 will remain up. The tooth 289 willencounter said catch, the safety stop will be stopped and the clutch dogwill be disengaged from the wheel and the press will automatically stop.

, It will be understood. that the safety mechanism and clutch mechanismwork so rapidly,that the press is started and stopped almost instantlywhen the operator so desires by operating the treadle rod. And the samething occurs when the safety stop acts.

It will be seen that there is an important advantage in having thesafety stop rod operated directly by a cam on the shaft, rather thanhaving it operated by the main slide as has been customary heretofore,in that the action of said safety rod becomes exactly synchronized withthe running of the press.

It will be apparent from the patent referred to that the first tool 50,that is the blanking punch, in this case represents a plurality oftools, and that the transferlocking the drive-wheel to and releasing, itfrom the shaft, of a reciprocating work transferring slide fortransferring the work to be acted upon by the tools in succession, saidtransferring slide having a safety hole, a reciprocating rod arranged toenter said hole when the work is properly centered with respect to thetools, and means under the control of said reciprocating rod forreleasing the shaft from the drive-wheel when the work is not centered,a pair of interconnected levers on the said shaft, a cam for operatingthe same and means for pivoting the said reciprocating rod to one ofsaid levers.

2. The combination with a plurality of reciprocating tools, a driveshaft for operating them, a. drive wheel, of a dog carried by the driveshaft for locking the drive wheel to and releasing it from the shaft, areciprocating work transferring slide for trans- I ferring the work tobe acted upon by the tools in succession, said transferring slide havinga safety hole, a reciprocating rod arranged to enter said hole when thework is properly centered with respect to the tools,

